Package g2101_2200.s2130_maximum_twin_sum_of_a_linked_list

Class Solution

java.lang.Object

g2101_2200.s2130_maximum_twin_sum_of_a_linked_list.Solution

public class Solution
extends Object

2130 - Maximum Twin Sum of a Linked List\. Medium In a linked list of size `n`, where `n` is **even** , the ith node ( **0-indexed** ) of the linked list is known as the **twin** of the (n-1-i)th node, if `0 <= i <= (n / 2) - 1`. * For example, if `n = 4`, then node `0` is the twin of node `3`, and node `1` is the twin of node `2`. These are the only nodes with twins for `n = 4`. The **twin sum** is defined as the sum of a node and its twin. Given the `head` of a linked list with even length, return _the **maximum twin sum** of the linked list_. **Example 1:**  **Input:** head = [5,4,2,1] **Output:** 6 **Explanation:** Nodes 0 and 1 are the twins of nodes 3 and 2, respectively. All have twin sum = 6. There are no other nodes with twins in the linked list. Thus, the maximum twin sum of the linked list is 6. **Example 2:**  **Input:** head = [4,2,2,3] **Output:** 7 **Explanation:** The nodes with twins present in this linked list are: - Node 0 is the twin of node 3 having a twin sum of 4 + 3 = 7. - Node 1 is the twin of node 2 having a twin sum of 2 + 2 = 4. Thus, the maximum twin sum of the linked list is max(7, 4) = 7. **Example 3:**  **Input:** head = [1,100000] **Output:** 100001 **Explanation:** There is only one node with a twin in the linked list having twin sum of 1 + 100000 = 100001. **Constraints:** * The number of nodes in the list is an **even** integer in the range [2, 105]. * 1 <= Node.val <= 105

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	pairSum(ListNode head)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

pairSum

public int pairSum(ListNode head)